The transportation and handling of large rolls of carpet and other material require that the carpet be wound upon a tubular carried member normally constructed from heavy cardboard. The blade of a forklift may be inserted in the bore of the tubular member for handling and moving the roll of carpet. The blade of the forklift sometimes punctures the inside bore structure of the cardboard tubular member resulting in damage to the carpet or other material rolled upon the tubular member adjacent the exterior surface thereof. When the roll of carpet is delivered to the wholesale or retail consumer, it is difficult to detect such a perforation or break in the cardboard or carpet until the carpet has been completely removed from the tubular carrier member. It is desirable to support a claim for damage that the roll of carpet be inspected at the time it is delivered.
While prior devices have been developed for generally detecting wear and erosion within the bore of a pipe such as shown in U.S. Pat. No. 3,139,686, such are entirely unsuitable for solving the instant problem due to the size and complexity of the devices.